Applying Domain-Driven Design and Patterns: With Examples in C# and .NET

If we try to categorize rules, we quickly find out that there are many dimensions to consider. For example, there are attributes such as the following:

• Where to execute (in which tier/layer)

• When to execute

• Degree of complexity (simple constraints, spanning several fields, spanning several instances, and so on)

• Starting actions or not

• And so on, and so forth

I'm sorry, but I won't be dealing with this much other than directing you to some other books on the subject, such as von Halle's book [von Halle BRA], the one by Ross [Ross BRB], and Halpin's [Halpin IMRD]. You will find that these books are pretty data-focused, but they are nevertheless highly interesting.

Let's try to get started from another angle. Let's define some principles and then get our hands dirty.